ecology/evolution dystopia question

absolutely. Back before our atmosphere was oxygen based, cyanobacteria evolved to be the first photosynthesizing plants. At this time, oxygen was toxic to all life on Earth, and the cyanobacteria created so much oxygen that Earth’s entire bacteria based ecosystem collapsed, and pulled so much methane out of the air that an ice age began. The cyanobacteria barely survived the event, but only because eventually other respiring life forms evolved and began utilizing the oxygen they produced.